The attacks on the Houthi rebels, which began Wednesday at the urging of internationally backed Yemeni leader Abd-Rabbu Mansour Hadi, have drawn angry reaction from Iran and raised fears across the region.

The airstrikes targeted sites around the main airport in the capital, Sana'a, and damaged homes in the area. Arab media also reported airstrikes on Yemeni airbases in the cities of Taiz, Hodeida and Sa'ada.

Several thousand Houthi supporters gathered by midday Thursday at Sana’a’s iconic city gate, Bab al-Yemen, chanting, "Death to America, death to Israel, a curse on the Jews and victory to Islam." A Houthi commander organized and led the protest.

Iran supports the Houthi rebels, who follow a similar form of Shia Islam. The Islamic Its foreign minister, Mohammad Javad Zarif, told Iranian TV that "the Saudi-led airstrikes should stop immediately, because it is against Yemen's sovereignty."

But a senior Iranian official ruled out military intervention.

Meanwhile, Arab television stations reported that Hadi arrived Thursday in the Saudi capital, Riyadh. His whereabouts were not publicly known after he fled the presidential complex in Aden on Wednesday as Houthi forces closed in on Yemen's main southern city.

Death toll

Houthi health officials say at least 18 people were killed and 24 others wounded in the Saudi airstrikes.

A VOA freelancer, Jacfar Kukay, said unconfirmed reports indicate at least three Houthi leaders were among those killed or wounded. Kukay said local media reported Houthi leader Mohamed Ali al-Houthi was injured after his home was hit, but his spokesman denied the report.

A Houthi Shi'ite fighter stands guard as people search for survivors amid the rubble of houses destroyed by Saudi airstrikes near Sana'a Airport, Yemen, March 26, 2015.

In Sana'a, a man wearing a firefighter's uniform told the Houthis' al-Maseera TV that Saudi and Arab planes had struck a number of civilian targets, killing women and children. The report had not been independently verified.

Arab League backs campaign

In Egypt, Arab foreign ministers meeting in the Red Sea resort of Sharm el-Sheikh agreed on a draft resolution to form a joint military force, according to Arab League Secretary General Nabil Elaraby. The development came as the Arab League pledged full support for the Saudi-led campaign in Yemen.

The resolution will be referred to Arab leaders at a summit on Saturday and Sunday in Sharm el-Sheikh.

Map identifying coalition members in support of Yemen against Houthis

Jordan, Egypt and Sudan confirmed their forces were taking part in the airstrike campaign, while Pakistan's foreign office said it is considering a request from Saudi Arabia to send troops.

The state-run Saudi Press Agency said Morocco had pledged to join as well, while the Saudi-owned al-Arabiya network said Saudi Arabia itself was committing 150,000 troops and 100 warplanes.

As bombings continued Thursday, forces loyal to Hadi recaptured Aden's international airport.

Saudi Arabia also suspended flights at airports near the country's southern border with Yemen.

Adel al-Jubeir, the Saudi ambassador to the United States, told reporters late Wednesday that the Saudis will do "anything necessary" to protect Yemen's people and its "legitimate government."

US logistical, intelligence support

The White House said the United States is coordinating with the Saudi-led military coalition and providing "logistical and intelligence support," but not taking direct military action.

U.S. Secretary of State John Kerry voiced support for the airstrikes in a conference call with Gulf foreign ministers. But United Nations Secretary-General Ban Ki-moon urged all U.N. member states to refrain from interfering in the conflict.

"The administration is having a degree of difficulty deciding who our friends are and who our enemies are," Corker said. "And so there is a lot of consternation about where America is in the Middle East, and you are beginning to see a shift of alliances, and it is creating some turmoil there."

Fellow Republican Senator Jeff Flake refrained from linking Washington-directed policy with the current crisis in Yemen.

"I don’t think anybody could have predicted what’s gone on the last month," Flake said. "I haven’t been enamored with the president’s foreign policy, but this one – it’s a tough neighborhood."

Analyzing situation

Yemen has sunk into violence and chaos since a popular uprising ousted longtime strongman President Ali Abdullah Saleh in 2012. Now, many Yemeni military units have joined the Houthis, raising worries of a civil war.

"Since the Houthis are supported by Iran, the great fear is Iranian involvement in the region, which most countries in the region are really, really afraid of," said Yiftah Shapir, a researcher on Arab militaries with Tel Aviv's Institute for National Security Studies.

Shapir said Iran did not initiate the conflict in Yemen, which has been going on for decades, but rather was defending its own strategic interests.

"If you try to look at the world from Iranian eyes, you see a very dangerous world, with Iran's greatest enemies actually surrounding Iran," he said.

However, Arab states see Iran's activities in Yemen as threatening their interests, Shapir said.

"The Iranians are taking very good advantage" of the Yemen confrontation, he said, "and by that put themselves in a position that endangers almost everybody in the region, especially Saudi Arabia."

While the confrontation is frequently attributed to the centuries-old Sunni-Shi'ite rivalry, analysts say there are many other factors.

Nevertheless, they say it adds to Middle East instability, which is being exploited, not only by Iran, but by radical Sunni groups such as al-Qaida and the Islamic State militant group.

Yemen expert Charles Schmitz, who teaches geography at Towson University in Baltimore, Maryland, told VOA that in the regional geo-strategic rivalry between Saudi Arabia and Iran, "the Iranians are very happy that they are causing the Saudis trouble in Yemen.

But he said he doubted Iran would get directly involved in the conflict – "at least not at this point.

"It really comes down to how quickly they come to a negotiated settlement and how far the [Saudi-led] military action is going to go," Schmitz said. "… A lot of it does depend on what happens to the military balance on the ground."